Safety and immunogenicity of two recombinant DNA COVID-19 vaccines containing the coding regions of the spike or spike and nucleocapsid proteins: an interim analysis of two open-label, non-randomised, phase 1 trials in healthy adults.

BACKGROUND: We assessed the safety and immunogenicity of two recombinant DNA vaccines for COVID-19: GX-19 containing plasmid DNA encoding the SARS-CoV-2 spike protein, and GX-19N containing plasmid DNA encoding the SARS-CoV-2 receptor-binding domain (RBD) foldon, nucleocapsid protein, and plasmid DNA encoding the spike protein. METHODS: Two open-label non-randomised phase 1 trials, one of GX-19 and the other of GX-19N were done at two hospitals in South Korea. We enrolled healthy adults aged 19-49 years for the GX-19 trial and healthy adults aged 19-54 years for the GX-19N trial. Participants who tested positive by serological testing for SARS-CoV-2 were excluded. At 4-week intervals, the GX-19 trial participants received two vaccine doses (either 1·5 mg or 3·0 mg), and the GX-19N trial participants received two 3·0 mg doses. The vaccines were delivered intramuscularly using an electroporator. The participants were followed up for 52 weeks after first vaccination. Data collected up to day 57 after first vaccination were analysed in this interim analysis. The primary outcome was safety within 28 days after each vaccination measured in the intention-to-treat population. The secondary outcome was vaccine immunogenicity using blood samples collected on day 43 or 57 after first vaccination measured in the intention-to-treat population. The GX-19 (NCT044445389) and GX-19N (NCT04715997) trials are registered with ClinicalTrials.gov. FINDINGS: Between June 17 and July 30, 2020, we screened 97 individuals, of whom 40 (41%) participants were enrolled in the GX-19 trial (20 [50%] in the 1·5 mg group and 20 [50%] in the 3·0 mg group). Between Dec 28 and 31, 2020, we screened 23 participants, of whom 21 (91%) participants were enrolled on the GX-19N trial. 32 (52%) of 61 participants reported 80 treatment-emergent adverse events after vaccination. All solicited adverse events were mild except one (2%) case of moderate fatigue in the 1·5 mg GX-19 group; no serious vaccine-related adverse events were detected. Binding antibody responses increased after second dose of vaccination in all groups (p=0·0002 in the 1·5 mg GX-19 group; p<0·0001 in the 3·0 mg GX-19; and p=0·0004 for the spike protein and p=0·0001 for the RBD in the 3·0 mg GX-19N group). INTERPRETATION: GX-19 and GX-19N are safe and well tolerated. GX-19N induces humoral and broad SARS-CoV-2-specific T-cell responses. GX-19N shows lower neutralising antibody responses and needs improvement to enhance immunogenicity. FUNDING: The Korea Drug Development Fund, funded by the Ministry of Science and ICT, Ministry of Trade, Industry, and Energy, and Ministry of Health and Welfare.

Exercise-based pulmonary rehabilitation for a post-COVID-19 pulmonary fibrosis patient: A case report.

RATIONALE: Pulmonary fibrosis is an infamous sequela of coronavirus disease 2019 (COVID-19) pneumonia leading to long-lasting respiratory problems and activity limitations. Pulmonary rehabilitation is beneficial to improve the symptoms of lung fibrosis. We experienced a post-COVID-19 pulmonary fibrosis patient who received a structured exercise-based pulmonary rehabilitation program. PATIENT CONCERNS: This article presents a case of successful pulmonary rehabilitation of a patient with post-COVID-19 pulmonary fibrosis. The patient could not cut off the oxygen supplement even after a successful recovery from COVID-19. DIAGNOSIS: Diagnosis of COVID-19 was based on the reverse transcription-polymerase chain reaction (RT-PCR). Pulmonary fibrosis was diagnosed by patient's complaint, clinical appearance, and computed tomography (CT) on chest. INTERVENTION: The patient underwent ten sessions of exercise-based rehabilitation program according to Consensus Document on Pulmonary Rehabilitation in Korea, 2015. OUTCOME: On the 8th day, he could cut off the oxygen supplementation and complete the one-hour exercise without oxygen. He was discharged after completing the 10-session program without any activity limitations. LESSONS: Exercise-based pulmonary rehabilitation will help the post-COVID-19 pulmonary fibrosis patients. This case suggested the importance of pulmonary rehabilitation program to the post-COVID-19 pulmonary fibrosis patient.

Ultrasensitive Detection of 25-hydroxy Vitamin D3 in Real Saliva Using Sandwich-type Electrochemical Aptasensor

We developed a novel sandwich-type electrochemical aptasensor to detect 25-hydroxy vitamin D3 (25OHVD3), which has high related to various disorders, such as osteoporosis, mental illness, and coronavirus disease 2019. We fabricated heterogeneous nanostructures comprising molybdenum disulfide and an electrochemically reduced graphene oxide composite for amplifying the electrochemical signal. To enhance the sensing performance by applying the sandwich-type strategy, methylene blue-labeled 1,2,4-triazole-3,5-dione (MB-TAD) was functionalized on an electrochemical aptasensor, wherein, MB as a redox mediator in the electrochemical aptasensor is responsible for electron production, and TAD can combine with 25OHVD3 to form aptamer/25OHVD3/MB-TAD complexes. The binding events of 25OHVD3 were studied by monitoring differential pulse voltammetry signals. Moreover, 1,6-hexanedithiol was functionalized on the electrochemical aptasensor to prevent nonspecific binding with proteins present in the saliva and to reduce the steric hindrance between aptamers. The detection capability of the electrochemical aptasensor exhibited a linear detection range of 0.1–150ng/mL, with a limit of detection of 0.02ng/mL. Furthermore, the electrochemical aptasensor selectively detected 25OHVD3 from other vitamins and further revealed the possibility of detecting 25OHVD3 in the saliva. Our results suggest that the electrochemical aptasensor based on the sandwich-type method is a highly selective and ultrasensitive method with immense potential for the quantitative detection of vitamins in saliva.

In Vitro Replication Inhibitory Activity of Xanthorrhizol against Severe Acute Respiratory Syndrome Coronavirus 2.

In spite of the large number of repositioned drugs and direct-acting antivirals in clinical trials for the management of the ongoing COVID-19 pandemic, there are few cost-effective therapeutic options for severe acute respiratory syndrome (SARS) coronavirus 2 (SCoV2) infection. In this paper, we show that xanthorrhizol (XNT), a bisabolane-type sesquiterpenoid compound isolated from the Curcuma xanthorrhizza Roxb., a ginger-line plant of the family Zingiberaceae, displays a potent antiviral efficacy in vitro against SCoV2 and other related coronaviruses, including SARS-CoV-1 (SCoV1) and a common cold-causing human coronavirus. XNT reduced infectious SCoV2 titer by ~3-log10 at 20 µM and interfered with the replication of the SCoV1 subgenomic replicon, while it had no significant antiviral effects against hepatitis C virus and noroviruses. Further, XNT exerted similar antiviral functions against SCoV2 variants, such as a GH clade strain and a delta strain currently predominant worldwide. Neither SCoV2 entry into cells nor the enzymatic activity of viral RNA polymerase (Nsp12), RNA helicase (Nsp13), or the 3CL main protease (Nsp5) was inhibited by XNT. While its CoV replication inhibitory mechanism remains elusive, our results demonstrate that the traditional folk medicine XNT could be a promising antiviral candidate that inhibits a broad range of SCoV2 variants of concern and other related CoVs.

Bio-inspired Ag nanovilli-based sandwich-type SERS aptasensor for ultrasensitive and selective detection of 25-hydroxy vitamin D3.

Vitamin D has been identified as an essential biomarker for various diseases such as rheumatoid arthritis, cancer, and cardiovascular diseases. Recently, many reports have demonstrated a potential link between vitamin D and systemic infections, including coronavirus disease 2019. The villi of the small intestine increase the surface area of the intestinal walls, demonstrating exceptionally efficient absorption of nutrients in the lumen and adding digestive secretions. In this study, based on the villi structure, we developed a bio-inspired silver nanovilli-based sandwich-type surface enhanced Raman scattering aptasensor for the ultrasensitive and selective detection of 25-hydroxy vitamin D3. The densely packed nanovilli structure enhanced the Raman signal, forming hotspots owing to its large surface area. Using experiments and electromagnetic simulations, we optimized the nanovilli structure as a SERS sensor. The sandwich-type aptasensor was designed using an aptamer and 4-Phenyl-1,2,4-triazoline-3,5-dione-methylene blue complex. The nanovilli-based aptasensor could sensitively detect various concentrations of 25-hydroxy vitamin D3, ranging from those found in deficient to excess conditions. The detection limit of the nanovilli-based sandwich-type aptasensor for 25-hydroxy vitamin D3 was 0.001 ng/mL, which is much lower than the deficiency concentration, and was detectable even in the human serum. In addition, our proposed sensor exhibited good repeatability (17.76%) and reproducibility (7.47%). Moreover, the nanovilli-based sandwich-type SERS aptasensor could selectively distinguish 25-hydroxy vitamin D3 from other vitamins. The silver nanovilli-based sandwich-type surface enhanced Raman scattering aptasensor opens a new avenue for the development of a bio-inspired vitamin-sensing platform.

Wide-range direct detection of 25-hydroxyvitamin D3 using polyethylene-glycol-free gold nanorod based on LSPR aptasensor.

Vitamin D is associated with various diseases such as obesity, digestive problems, osteoporosis, depression, and infections, which has emerged as an interest in public healthcare. Recently, vitamin D has received more attention because of the potential implication with coronavirus disease 2019. In this study, we developed a localized surface plasmon resonance (LSPR) aptasensor based on polyethylene-glycol(PEG)-free gold nanorods (AuNRs) for the wide-range and direct detection of 25-hydroxyvitamin D3. The surfactant on AuNRs was removed by exchanging with polystyrene sulfonate (PSS) instead of PEG then the PSS was exchanged with citrate. By exchanging the stabilizer of AuNRs from PEG to PEG-free (i.e., citrate), the sensing efficiency of LSPR aptasensor was significantly improved. Additionally, LSPR aptasensor was functionalized with aptamer and blocking agent to enhance the sensing performance. The LSPR aptasensor achieved the direct, highly sensitive, and selective detection of 25-hydroxyvitamin D3 over a wide concentration range (0.1-105 ng/mL), with a limit of detection of 0.1 ng/mL. This detection range included the concentration of vitamin D from deficiency to excess. The PEG-free AuNR-based LSPR aptasensor affords a new avenue for the development of robust sensing technology for vitamins.

Genome Sequences of Two GH Clade SARS-CoV-2 Strains Isolated from Patients with COVID-19 in South Korea.

We report the genome sequences of two GH clade severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains isolated from nasopharyngeal swabs from patients with coronavirus disease 2019 (COVID-19) in South Korea. These strains had two mutations in the untranslated regions and seven nonsynonymous substitutions in open reading frames, compared with Wuhan/Hu-1/2019, showing 99.96% sequence identity.

An infectious cDNA clone of a growth attenuated Korean isolate of MERS coronavirus KNIH002 in clade B.

The MERS-CoV isolated during the 2015 nosocomial outbreak in Korea showed distinctive differences in mortality and transmission patterns compared to the prototype MERS-CoV EMC strain belonging to clade A. We established a BAC-based reverse genetics system for a Korean isolate of MERS-CoV KNIH002 in the clade B phylogenetically far from the EMC strain, and generated a recombinant MERS-CoV expressing red fluorescent protein. The virus rescued from the infectious clone and KNIH002 strain displayed growth attenuation compared to the EMC strain. Consecutive passages of the rescued virus rapidly generated various ORF5 variants, highlighting its genetic instability and calling for caution in the use of repeatedly passaged virus in pathogenesis studies and for evaluation of control measures against MERS-CoV. The infectious clone for the KNIH002 in contemporary epidemic clade B would be useful for better understanding of a functional link between molecular evolution and pathophysiology of MERS-CoV by comparative studies with EMC strain.